1. Field of the Invention
The present invention relates generally to cooling air flow devices for agricultural harvesters such as cotton pickers and strippers, and, more specifically, to a cleaning device for a rotating screen air cleaner on such harvesters.
2. Related Art
Agricultural combines and cotton harvesters operate in severe conditions with much dust and plant debris. The hydraulic oil, air conditioner systems, and internal combustion engines of these harvesters require a large volume of partially filtered air for proper cooling. A self-cleaning, rotating inlet screen located adjacent an engine compartment has been employed to remove chaff, leaves and other large particulate matter from the cooling air stream to avoid blockages in the heat exchangers behind the screen. Such devices are shown, for example, in U.S. Pat. Nos. 5,183,487; 4,906,262; 4,542,785; 4,233,040; and 3,837,149.
Various types of vacuum devices, some in combination with shear bars to break up trash into smaller pieces such as shown in the aforementioned U.S. Pat. No. 4,233,040, are available to clean the screen. Often these types of devices fail to eliminate screen plugging problems, especially in cotton harvesters wherein cotton lint can ball up adjacent the screen cleaner. Most of the available devices rely primarily on vacuum, making them prone to clogging, and removal of the screen debris a substantial distance from the harvester area often is not possible. Problems of inadequate debris removal are particularly acute in cotton pickers and strippers where the characteristics of cotton lint and leaves causes such debris to build up quickly and easily on areas of the harvester. Cotton trash that bunches up near the trash ejection area often cannot be removed by the shear bars, and build-ups ultimately disable the cleaning system.
Many of the cleaning systems rely on direct vacuum from the engine cooling fan which reduces cooling capacity and circulates trash through the engine compartment. Systems such as shown in U.S. Pat. No. 4,542,785 require a separate fan, and trash removed from a fixed screen in the system must be passed through the fan.